To fully understand the intricacies of our latest project, the Colorado State Capitol Subbasement Repair, we go back to the fundamentals of information-gathering with the 5 W’s – Who, When, Where, What, and Why for this historic repair project of a 128-year-old building in downtown Denver.
WHO
Andrew Carnegie said it best, “Teamwork is the ability to work together toward a common vision. The ability to direct individual accomplishments toward organizational objectives. It is the fuel that allows common people to attain uncommon results.”
Project Team Members:
- HPM, Inc. & Apollo Mechanical Joint Venture (HPM-Apollo) – General Contractor/Mechanical Contractor
- Diamond Drilling – Concrete Demolition
- Orion Environmental – Environmental Remediation
- Guarantee Electrical Contracting – Electrical
- BCER Engineering – Engineer of Record
- TreanorHL – Architect of Record
The project team for this subbasement repair project exemplified this collaborative teamwork environment and achieved the impossible. They overcame numerous challenges and instilled a true sense of ownership and accountability for every team member to deliver this project successfully for Colorado’s governing body. The project team banned together, working in a hot and compact subterranean environment with only two small windows (3′ x 5′) as their primary access points for excavation material removal and pumping concrete.
From discovering previously unknown asbestos under the existing slab to managing the intricacies of a live construction site in a fully operational historic building, this team overcame complex challenges to prepare for future modernization work at the prominent Capitol building.
WHEN
The project timeline spanned from January 1, 2021, to June 30, 2022.
The construction team achieved several milestones throughout the project’s duration that spoke to the quality of the team’s leadership to achieve extraordinary results. As a public project, budgets and timelines are even more crucial, especially when this six-month project turned into 12-months upon the discovery of asbestos. The project team communicated early and often with the owner’s representative and end-users, including security personnel, cleaning staff, and the legislative members, regarding project safety requirements and realistic time allowances to safely abate the asbestos.
Once the project team cleared the working area from the asbestos, the team shifted to an “all-hands-on-deck” mentality to complete the repairs by the June 30, 2022, deadline, when public funding for this project was mandated for expiration. This push involved several iterations of 20-hour shifts where team members, previously not in leadership roles, stepped up and volunteered to be shift leaders to take ownership of completing this project successfully.
WHERE
The Colorado State Capitol is located in the heart of downtown Denver, at 200 E. Colfax Ave.
As with most projects downtown, there is limited “extra space” for construction sitework. This project was no different, such that even though the entire project spanned 46,000 SF, access to the subbasement was extremely limited for the demolition and excavation work and completed concrete pours. The sparse construction site required the team to immerse itself in months of pre-planning to devise a multi conveyor belt system to remove the excavation materials and create a strategy for the concrete placements into the basement through a punched-out window well.
WHAT
This municipal project required the construction team to hand-excavate 1,200 cubic yards of dirt in the confined subbasement of a 128-year-old building to set the foundation for future modernization of Colorado’s legislative branch. The project team employed several resourceful and innovative solutions to overcome the challenges of this intricate project that significantly impacts the nearly 300,000 visitors each year to the State Capitol and about 70,000 that receive guided tours of this public-facing building.
Resourcefulness
The project team devised resourceful solutions to overcome the limitations of a sparse construction site that included a multi conveyor belt system to remove the excavation materials and a creative strategy for the concrete placements into the basement through a punched-out window well.
With five small conveyors, the team hand-excavated dirt via buckets and then transferred it to electric-powered buggies that moved the material to the window well for conveyors to remove from the building.
To accommodate the concrete placements, the team ran a slickline through a punched-out window (3’ x 5’) to pump concrete into the subbasement from the upper level where the pump truck was. A ten-person placement crew was required to move and modify the slickline during the concrete placements that were sometimes over 200′ from the pump truck and snaked through the sub-basement structure.
Another solution came about unexpectedly, as asbestos was discovered after the team already had two concrete pours completed. This unforeseen condition brought the project to a halt to assess the abatement, find a qualified team, and re-sequence the overall project schedule and plan. Despite this disruption, the project team reorganized its members to accommodate a more detailed process involving working in quadrants throughout the basement area. Once the abatement team removed all asbestos-containing materials (ACM) from one location, the project team would request an inspection from the State. The State would review the work, and then the abatement team would remove the double-containment walls for that area. This process allowed the project team to move forward and excavate the rest of the material in a process that HPM’s Superintendent described as trying to put multiple pieces of a jigsaw puzzle together without visual aids.
Innovation
The limited site area and unforeseen conditions for this Capitol project necessitated the innovative use of construction techniques and manpower to complete the project before the start of a new fiscal year for the State. Site access drove most of the project’s decision-making. The project team was designated a small plot of land on one of the Capitol lawns and a limited area in an adjacent parking lot where pump trucks could drive up to access the window well for materials distribution. At one point, the team was stacking transformers inside the building and brought out a crane company to erect a chain scaffold with only about 1.5’ of clearance. The near-exact rigging process left little to no room for error to safely bring all materials into and out of the basement.
During excavation, there were a few areas where the team would excavate the trench, and material would sluff out from under the adjacent walls supported by the concrete. As a result, the team had to devise a plan to stabilize the existing foundation’s support. In addition, settlement and elevation changes across the entire sub-basement were a complicated issue, with a total of 6″ floor elevation differences across the building, requiring the team to constantly adjust existing doorways and openings throughout.
The team was also required to perform structural modifications to the building in multiple locations throughout the job, including adding new access pathways through existing structural walls up to 36″ thick from the original masonry walls. This process required saw cutting and hand removal of masonry, adding new W-shape lintels to the full depth of new openings, and replastering walls to match the original finish.
In addition, the project team self-performed most of the project scope, which included: steam piping, condensate piping, domestic hot and cold water, sanitary and storm sewer, chilled water supply and returns, as well as all concrete and excavation work. The project team effectively managed this project through:
- Detailed scheduling to determine who could safely work on site each day
- Consistent communication via daily work logs
- Building trust among all team members who had to work closely in an extremely limited site for long periods with a zero-incident rate
WHY
We heard from Andrew Carnegie at the start, now let’s end with some wise words from Ralph Marston, “Remember why you started, remember where you’re headed, think of how great it will be to get there, and keep going.”
At HPM Contracting, our biggest “why” is always our clients and the end-users of the projects we build. The Colorado State Capitol Subbasement repair project significantly impacts Coloradoans and visitors to the Capitol because it was a critical component for future modernizations of a structure originally built in the 1890s. With nearly 300,000 visitors each year to the State Capitol and about 70,000 that receive guided tours of this public-facing building, ensuring end-user comfort is critical to Colorado’s governing body and visitors.
The project team’s work set the stage for the relocation of utilities and modern amenities to be installed into the Capitol building, increasing people’s comfort levels while visiting this historical landmark. In addition, the project team was awarded three rare commemorative tokens of gratitude for being professional, competent, and capable and for having a shared vision to “provide service and commitment that consistently exceeds our customers’ expectations!”
Thank you again to the entire project team for the successful completion of this historic building!
